Improvement in burglar-alarms



W. FISCHER.

BURGLAn-ALARM.

' No.185,733 Patented De.ze,1a7e.

UNITED STATES PATENT OFFICE.

WILLIAM FISCHER, OF WASHINGTON, D. O., ASSIGNOR OF ONE-HALF OF HIS RIGHTTO FRANCIS A. OLAVELOUX, OF SAME PLACE.

IMPROVEMENT IN BURGLAR-ALARMS.

Specification forming part of Letters Patent No. 185,738, dated December26, 1876; application tiled November 29, 1876.

To all whom it may concern Be it known that I, WILLIAM FISCHER, ot'Washington, in the county of Washington and District of Columbia, haveinvented certain new and useful Improvements in Burglar-Alarms; and I dohereby declare that the following is a full, clear, and exactdescription thereof, which will enable others skilled in the art towhich it appertains to make and use the same, reference being had to theaccompanying drawing, which forms a part ot' this specification, and inwhich- Figure l is a side elevation. Fig. 2 is a similar view, showingthe alarm set. Fig. 3 is a top plan; and Fig. 4 is a front elevation.

Similar letters of reference indicate corresponding parts in all thefigures.

My invention relates to that class of burglar-alarms in which the alarmis given by the explosion of a cartridge; and it consists in theconstruction and combination of parts, substantially as hereinafter morefully described, and pointed out in the claims.

In the drawing, A is a casting, about three and a half inches long, andhaving three od'- sets, a b c. a and b are perforated to allow a bolt,B, to pass through, and c has a cartridgesocket, O. D is thetrigger-lever, hinged at d in the middle offset or bracket b, andterminating in a sharp point or prong, e. The upper end of lever l) hasa notch or recess, jl E is a spiral spring, coiled around bolt B,between the brackets a and b, as shown, and abutting at its lower endagainst a pin, g, which passes through bolt B, projecting on both sidesthereof. F is a guard, to prevent the premature explosion of thecartridge, which consists of a pin aflixed between two pieces of wire,which are pivoted in the sides of the lowermost bracket c.

When this guard is in the position shown in Fig. l, it will prevent thehammer h ot' bolt B from striking the cartridge; but when swung overtothe position represented in Fig. 2, the hammer will, on its descent,explode the cartridge.

To the upper back part of the casting A are afxed two sharp points orspurs, a', and bolt B has affixed to it a ring, G, used in setting thealarm.

This operation will be readily understood from the foregoingdescription, and by reference to Fig. 2 of the drawing. Bolt B is, byits ring G, pulled up until pin g reaches the top ofthe trigger-lever D,when this is turned in so as to have pin g restin its notchf. Thecartridge is then inserted, and the alarm is placed against the door orwindow which it is desired to guard, in the position represented in Fig.2-that is, the point e is forced into the floor, the other two spurs, aa', being pressed into or against the door or windowsash, as the casemay be. When in this position, pressure against the alarm, by openingthe door, for instance, will release the hold ot' the trigger D upon ping, and the coiled spring E will force the hammer down against thecartridge and explode it, the guard F having been previously arranged soas to interpose no obstacle; but this should not be done until after thealarm has been secured in its position, so as to prevent prematureexplosion by the trigger slipping otf pin g during the operation ofsetting the alarm.

When placed in the position shown in Fig. 2, with the point e insertedinto the upper rail of a winilowsash, and the spurs a. a against thewindow-casing, the raising ofthe sash will have a similar effect ofoperating the alarm and exploding the cartridge.

Tous, my improved alarm may be used for windows and doors both, and whenproperly placed, as herein described, will never fail to operate.

The advantages of this alarm over others are, simplicity and cheapnessof construction, the parts heilig' few and simple. It is not, therefore,liable to get out of order, as are the more complicated alarms of thisclass; second, it cannot possibly fail to operate it' properly set;third, the se. ting requires no previous preparation ot the door orwindow, no cords or nails being required, but it can be set inlstantaneonsly at any door or window; and, inally, there is absolutely nodanger ot' premature explosion, as the guard is not placed so as toexpose the cartridge tothe blow of the hammer until the alarm is in itsproper position.

Having thus described my invention, I

claim and desire to secure by Letters Patent of the United States- 1. Aburglar-alarm, consisting essentially of a frame piece, A, armed withspurs a' a', and having a cartridge-socket, C, a hammer, B'. and alever-trigger, D, havingl a point or spur, e, combined to operatesubstantially in the manner and for the purpose liereinbefore set forth.

2. In a burglar-alarm, a triggerlever armed with a point or spur, e,whereby the said lever may be secured firmly in the oor or Windowsash,substantially as and for the purpose herein shown and set forth.

3. The combination ofthe frame or case A, armed with spurs a a', withtriggerlever D, armed with point or spur e, substantially as and for thepurpose herein shown and set forth.

4. In combination with frame A, having cartridge-socket C, the guard F,constructed and arranged substantially as and for the purpose hereinshown and specified.

5. As an article ot' manufacture, the improved bnrglar-alarm hereindescribed, cousisting of frame A, having spurs a a and 0E- sets orbrackets a, b c, bolt B, having hammer h, ring G, and pin or shoulder g,coiled spring E, trigger-lever D, having point or spur e, and notch f,and guard F, all constructed and combined to operate substantially inthe manner and for the purpose herein shown and specitied.

In testimony that I claim the foregoing as my own I have hereto aixed mysignature in presence of two witnesses.

WILLIAM FISCHER.

Witnesses:

LOUIS BAGGER, C. A. SNOW.

